1. Field of the Invention:
The present invention relates to apparatus for unloading the material from storage, such as a silo. More particularly, this invention relates to a silo discharging device with a conveying element leading to a discharge opening and means for unloading substantially uniformly across the bottom of the silo.
2. Description of the Prior Art:
As is known, material, such as silage and the like, is frequently stored in upright cylindrical storage containers known as silos. The material that is fed into the silos is frequently compacted to a considerable extent such that removal is difficult with the prior art devices.
The prior art devices for unloading a silo have been varied. They have included the crude windows in the side of the cylindrical wall to allow access to the interior for manual unloading. This has required means for ingress and egress from the respective windows in the walls and required manual labor for the unloading. Attempts to employ augers extending from the top downwardly into the silage has not proven successful. A more successful approach has been the use of bottom unloaders in which one or more radially extending augers, or auger cutting arms, have traversed around the bottom of the silo for unloading from the bottom the silage and the like. In the past, these augers have had uniformly spaced flights thereon such that flights at the radially exterior end of the auger were always filled. Consequently, no further silage was removed near the center and the augers tended to stall for lack of feeding material. Frequently, there occurred bridging with the center material piling up on the housing or the like. Conversely, there occurred frequently a caving of the material with uneven unloading of the silo.
The devices that have been employed for bottom unloaders have ranged from that described in early U.S. Pat. No. 1,274,548 with the radially extending augers having uniformly spaced flights through powered means such as described in U.S. Pat. No. 3,356,235, also having uniformly spaced flights on the auger; to U.S. Pat. No. 3,266,117 having rotary motor driven cutters located above the conveying element to try to solve this problem. U.S. Pat. No. 3,666,117 also employed unevenly spaced flights with the very expensive approach of having to taper the floor of the silo, or other elaborate means to try to obtain a solution to the problem.
As will be apparent from the foregoing, the prior art has not provided totally satisfactory apparatus for storing and unloading the stored material from the bottom of a silo and the like.